Abstract
Abstract: :
Purpose: To introduce the Portal Color Sort Test (PCST), a computer-based test of color vision, and to compare it to the Farnsworth-Munsell (FM) 100 Hue test (FMHHT) in normal subjects. The FMHHT is a widely accepted instrument for the testing of color discrimination. Its advantage over other psychophysical tests of color discrimination is its ability to distinguish trichromats into categories (superior, average, and poor). Its disadvantages include the need for special ambient illumination and the length of time it takes for its completion. The touch screen computer-based Portal Color Sort Test (PCST) has a design similar to the FM 100-Hue but consists of only 36 color plates in 4 sets of 9 plates. The test is based on the accuracy with which an individual arranges each set of 9 plates on a computer screen from one shade of one color to another shade of another color. Methods: 10 subjects with presumed "normal" trichromatic vision and without known eye disease have been recruited to date. Each subject underwent a series of color vision tests that included the 15 plate Ishihara test, the D-15 FM test, the FM-100 hue test and the PCST under rigorous standardized conditions and as recommended by the respective manufacturers. The PCST was administered twice; once at the beginning and once at the end of the session. Tests were recorded and scored according to the manufacturers' instructions. Results: Of the ten trichromats tested, 3 received "Superior" scores (<20) on the FMHHT and received a score of 0 (no error) on the PCST. 7 subjects tested "Average" (score = 20-100) on the FMHHT and had error scores of 0 to 12 (average 5.57) on the PCST. On repeated administration of the PCST, all but one of these 7 subjects received a perfect score of 0. The one subject who had a score of 4 on his second attempt had the highest error score of 12 on the first attempt, and the second highest error score on the FMHHT; he probably has poorer color discrimination than the rest of subjects in the FMHHT "Average" category. The average time to complete the FMHHT was 14 minutes. The average time to complete the PCST was 3 minutes. Conclusions: Our preliminary results indicate that the PCST allows an approximately 4 – 5 times faster testing of color discrimination than the FMHHT. Subjects who have excellent color discrimination ability on the FMHHT have perfect scores on the PCST; those with average color discrimination ability on FMHHT have error scores of 0-12 on the PCST. Additional data is currently being collected to define the range of scores in the different categories of color discrimination abilities on the PSCT, including patients with known color vision defects.
Keywords: color vision • clinical (human) or epidemiologic studies: sys • clinical laboratory testing